CAN FD (CAN with Flexible Data-rate) was introduced by Bosch in 2012 to overcome the Classical CAN's bit rate limitation to 1 Mbps and to expand the number of data bytes per CAN frame from up to 8 to up to 64, thereby closing the gap between Classical CAN and other protocols.
This is achieved by a modified CAN frame format where the bit rate can be switched to faster value inside the CAN frame and by a new data length coding.
CAN FD is standardized as ISO11898-1:2015. CAN FD protocol controllers are also able to perform Classical CAN communication.